As you have a G5, if you're looking to make a clone which would start your machine, you'll need FireWire. If it's just for Time Machine then USB will suffice.
Eric, as a footnote only:
Firewire (especially FW 800 is great. But if you only have an INTEL mac and have no other firewire Macs -- even FW400, any USB2 drive formatted for "Mac OS Extended (journaled)" will boot it. Earlier Macs (see Mick above) DO need Firewire.
Considerations:
Most new drives come formatted with one or other Windows formatting. This is fine if you just want to store photos, but If you want to Clone your OS, use it as a startup drive, or store OSX programmes on it, the whole drive must be reformatted with Apple format "Mac OS Extended (Journaled)" before you make any partitions -- use Disk Utility to make a "new" single partition, then make whatever number of smaller partitions you would like. 1TB is pretty massive as a single partition, and would be ungainly for general use. it's quick and simple. LaCie drives can be bought Mac-formatted, but you pay a price.
Macs without Firewire can't be started as a simple external hard drive should that ever be necessary.
Experience:
USB2 drives are inexpensive these days, I use LaCie with Firewire, and Western Digital (preferred) with Verbatim and Iomega too for USB2 only. All work fine as storage, as boot drives, and for Time Machine. Seagate drives were often the standard Apple-supplied drives in the old days, but it seems they have been going through a slightly bad quality patch recently. Western Digital are well-regarded and are my favourites.
Buying:
Robert Dyas
often do Verbatim drives (Samsung mechanism) at a moderate discount -- if you buy anything from their shops sometime during the week (ask them) you will see a 15% (or so) discount on anything you might buy on, maybe Saturday, or a Bank Holiday. 1TB ends up as about £50, 1.5TB is nearer £70.
PC World
do a deal as follows: you reserve your external Hard Drive on line, choose which store with stock you want to collect it from, and go to that store, pay and take it with you. Don't buy the "My Book -- for Mac" drives, as these carry a high markup instead buy the standard PC version and use Disk Utility to format them. Western Digital make a small and light "WD Essentials" drive (my current favourite) -- simple Disk Utility reformatting required (see above). 1TB ends up at about £45, 1.5TB also available.
Thank you, Euan; it's a superb G5, but not actually an Intel one; I'm waiting for Mick to upgrade himself again before I get one of those! Doing the crafty thing with PC World is what I'd tentatively planned but I was digitizing a few records first. I'll have a go now.
It's arrived! I'm so excited.
I don't know what to do with it though.
I blithely pressed the Yes button when it asked me if I wanted to use it for Time Machine and it gave me a quick countdown then proceeded to back up the entire computer: which I hadn't really intended to do since three quarters of it consists of backups anyway. It was a bit like that scene towards the end of Alien when a voice says, "PARP - SHIP WILL DETONATE IN NINE MINUTES - PARP". You don't know quite what to do.
I'll figure it out by the morning.
Eric,
You have done me a favour with your enquiry about external hard drives so that i got the benefit of the various replies. I am going to get one to attach to a recently acquired laptop and a friend had already pointed me in the direction of Western Digital, so WD it will be with Firewire and USB connection.
I had incidentally noted your (now some time ago) enquiry about Broadband in France. We spend quite some time there and have broadband via Orange. I am looking to change as Orange only seems reasonable value (poor by UK standards) if you take their whole phone and TV bundle. We are also less than happy with the speed we get there. So I may also need to do other checks before making a move. Possibly if you spend some time in France we might be able to exchange notes.
Hi, John,
I do spend a lot of time there but I was only enquiring on behalf of an ami. I don't think his wife will let him anyway though! They actually spend most of the year there and I wondered if it would be practicable to have a broadband that wasn't territorial, i.e. you wouldn't have to pay for it twice, once in each country. I'm sure it's possible since one can receive French TV over here via satellite.